Expanding reamer



(No Model.)

- B. I'. SISSON.

BXPANDING BEAMER. No. 245,023. Patented Aug. 2,1881.

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` UNITED STATES- PATENT OFFICE.

BENJAMIN F. S'ISSON, OF MINNEAPOLIS, MINNESOTA.

YEXPANDINC? REAMER.

SPECIFICATION forming. part of Y Letters Patent No. 245,023, dated August 2, 1881. Application inea May 9, 1881. (No model.)

To all whom it may concern:

Beit known that I, BENJAMIN FRANKLIN SIssON, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented a certain new and useful Improvement in Expanding Beamers, of which the following is aspeciication. i p

This invention relates to that class of implements known as expanding reamersg' and it consists in a reamer formed with slits cut through its upperpart, and with a conical interior adapted to be drawndown over a conical mandrel to expand the reamer so as to increaseits diameter or restore its former size when worn, as hereinafter'setlbrth. Ifattain these objects by the use of the mechanism illustrated in the accompanying drawings, in

whichi Figure 1 is a partly-sectional side view. Fig. 2 is a completeside view, and Fig. 3 isa topplan view.

A is a hollow reamer, provided with the cutting ribs or faces a in the ordinary maner, and with the upper part of the interior slightly conical and adapted to t down over a somewhat larger conical mandrel, B, to which it is coupled or otherwise secured by pins or lugs b, so as to be revolved therewith.

c c c c are slits cut through the upper part of the reamer, except small portions at d. When the reamer is first formed and the slit c cut therein it may be used as an ordinary reamer until it becomes dulled and requires regrinding. This of course reduces its-size; hence to 'restore its size a Wedge-shaped plug is driven intoVt-he hole e in the upper end of thereamer until one of the solid portions, d is split open. Then a screw, g, is inserted through the hole e and the mandrel B drawn up into the reamer A, the screw having previously been tapped into the upper endvof the mandrel. This will expand the reamer by means of the slit c, extending below the part d that has been broken by the wedge-shaped plug, and if a greater degree of expansion is required two or more ot' the parts ol may be split open. By this means the reamer may be expanded to any desired extent within the limits of the strength of the metal. Y

Between the top of the mandrel B and the inside of the hollow reamer A washers h of varyin g thicknesses will be placed, so that the reamer may be expanded to any desired degree, as it will be readily seen that if a thin washer be placed in the mandrel the reamer will be drawn'down over the mandrel more than ifa thick washer were used; hence the size of the reamer may be perfectly regulated by the thickness of the Washers used.

What I claim as new is- 1. Anexpandingreamer consistingot'aluted or grooved shell, A, conical within its interior, and having slits c cut through its body except at its outer end, where they extend but partially therethrough, and a conical mandrel, B, whereby the parts are adapted to operate as set forth.

2. The combination and arrangement of the fluted or grooved reamer A, provided with the slits c and made conical on the interior, and the conical mandrel B, and 'regulating-washer h, and screw g, substantiallyas set forth.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

BENJAMIN FRANKLIN SISSON.

Witnesses:

P. W. HERZOG, E. O. OHATFIELD, 

